i have mine in my bathroom under the sink. its not hard to mess with the plumbing, i cannot remember what the part is called but it screws into the copperline, piercing it and thats how you get an easy connection. the parts name is slipping me though, but hardware stores carry them for a few bucks. theyre in the RO section ( its what people use if their hooking a RO to their fridge ) its very easy to do.
i drilled into my sinks drain line and plumbed in a quick connect for the waste water. this way i dont have to deal with it as im in a second floor apartment.
back home i would barrel the waste water and use it to fill the washing machine. cant really do that here.
for water i use x2 20gallon brute trash cans. 1 for saltwater, 1 for RO/DI water. if your working with a smaller tank, 2 clean buckets can work.
when i make my water i sit my trashcan into the bath tub, run the hose to it and run it through a small hole thats on the handle of the can, then clamp it to the can too before turning on my water. it comes out in a slow drip but doing it this way if i for some reason forget it, it will just overflow into the tub and not the floor. i havnt forgotten it here yet, but i did have the hose work its way out of the bucket without me noticing ( hence the clamp now )
my downstairs neighbor comes up and knocks to check to make sure the toilet isnt leaking again ( i guess it did from previous owners ) i told him sorry, my hose fell on the floor from my fishtank and he goes oh your tank, must be a big tank as he peaks into my bathroom and sees a big trashcan full of water. i just smiled ( mistake on my part, i should have just said it was the toilet overflowing as im not even sure if tanks are allowed in my lease lol shhh )